Forum Discussion
Exchange Hybrid centralized email flow bypass issue
The inbound connector should be locked down depending on what you entered into the hybrid wizard, can you post the output of get-inboundconnector | fl
Please see command output. Note that I have a domain set under "TlsSenderCertificateName" but I now see that "RestrictDomainstoCertificate" is set to "False", is this the option to change to only accept emails from Hybrid Exchange?
I believe this needs to be set to true else this is just accepting any email as long as its TLS, you will need to test as much as possible because im not sure how this will handle the wildcard. See the value settings below.
Did this resolve your issue?
I did not get a chance to test the change but please take a look at this link that provides a different solution for exactly the same scenario https://o365info.com/configure-exchange-online-inbound-mail-flow-to-accept-smtp-connection-only-from-a-specific-mail-security-gateway-ip-address/